Thanks for this. I got a similar explosion on Win32 using
fork (pseudo-fork) and fixed it as you suggest by switching
to Storable::dclone. The bug could be replicated, but
depended strangely on input data and other interactions.
It also required lots of work to get an error message.
Initially it crashed with a Windows crash dialog and nothing
on STDERR. Nasty bug.

Went to join the gridlock to see it
Held an eclipse party
Watched a live feed
I cn"t see tge kwubosd to amswr thus
I tried to see it, but 8000 miles of rock got in the way
What eclipse?
Wanted to see it, but they wouldn't reschedule it
Read the book instead